千锋学习视频https://www.bilibili.com/video/BV1dP4y1c7qd?p=72&spm_id_from=pageDriver&vd_source=f07a5c4baae42e64ab4bebdd9f3cd1b3
1.React 路由
1.1 什么是路由？
路由是根据不同的 url 地址展示不同的内容或页面。
一个针对React而设计的路由解决方案、可以友好的帮你解决React components 到URl之间的同步映射关系。
1.2 路由安装
npm i react-router-dom@51.3 路由使用
javascript">import React, { Component } from 'react'
import {HashRouter,Route} from 'react-router-dom'
import Film from './views/Film'
import Cinemas from './views/Cinemas'
import Center from './views/Center'
export default class componentName extends Component {
render() {
return (
<div>
<HashRouter>
<Route path="/films" component={Film}></Route>
<Route path="/cinemas" component={Cinemas}></Route>
<Route path="/Center" component={Center}></Route>
</HashRouter>
</div>
)
}
}
<HashRouter> 会让路径带上一个/#
也可以把路由封装成一个组件抽离出去
javascript">
import React, { Component } from 'react'
import MyRouter from './MyRouter'
// import Film from './views/Film'
// import Cinemas from './views/Cinemas'
// import Center from './views/Center'
export default class componentName extends Component {
render() {
return (
<div>
{/* <HashRouter> 也可以把路由封装成一个组件抽离出去
<Route path="/films" component={Film}></Route>
<Route path="/cinemas" component={Cinemas}></Route>
<Route path="/Center" component={Center}></Route>
</HashRouter> */}
<MyRouter></MyRouter>
</div>
)
}
}
javascript">
import React, { Component } from 'react'
import {HashRouter,Route} from 'react-router-dom'
import Film from './views/Film'
import Cinemas from './views/Cinemas'
import Center from './views/Center'
export default class MyRouter extends Component {
render() {
return (
<div>
<HashRouter>
<Route path="/films" component={Film}></Route>
<Route path="/cinemas" component={Cinemas}></Route>
<Route path="/Center" component={Center}></Route>
</HashRouter>
</div>
)
}
}
1.4 路由重定向
如果没有匹配的路径，需要跳转到指定的路径 使用<Redirect from="" to="" />
javascript">
import React, { Component } from 'react'
import {HashRouter,Route,Redirect,Switch} from 'react-router-dom'
import Film from './views/Film'
import Cinemas from './views/Cinemas'
import Center from './views/Center'
export default class MyRouter extends Component {
render() {
return (
<div>
<HashRouter>
<Route path="/films" component={Film}></Route>
<Route path="/cinemas" component={Cinemas}></Route>
<Route path="/Center" component={Center}></Route>
{/* 匹配/路径的时候 模糊匹配 跳转到/films */}
<Redirect from="/" to="/films"></Redirect>
</HashRouter>
</div>
)
}
}
但是这个做法存在问题：当输入http://localhost:3000/#/center 会跳到center 但再次刷新又会跳到/films
改进：使用Switch 匹配一次后将不再继续匹配
javascript">
import React, { Component } from 'react'
import { HashRouter, Route, Redirect, Switch } from 'react-router-dom'
import Film from './views/Film'
import Cinemas from './views/Cinemas'
import Center from './views/Center'
export default class MyRouter extends Component {
render() {
return (
<div>
<HashRouter>
<Switch>
<Route path="/films" component={Film}></Route>
<Route path="/cinemas" component={Cinemas}></Route>
<Route path="/Center" component={Center}></Route>
{/* 匹配/路径的时候 跳转到/films */}
<Redirect from="/" to="/films"></Redirect>
</Switch>
</HashRouter>
</div>
)
}
}
精准匹配exact
场景：/ 跳转到/films 其他不匹配上述路由的跳转到404
javascript">
import React, { Component } from 'react'
import { HashRouter, Route, Redirect, Switch } from 'react-router-dom'
import Film from './views/Film'
import Cinemas from './views/Cinemas'
import Center from './views/Center'
import NotFound from './views/NotFound'
export default class MyRouter extends Component {
render() {
return (
<div>
<HashRouter>
<Switch>
<Route path="/films" component={Film}></Route>
<Route path="/cinemas" component={Cinemas}></Route>
<Route path="/Center" component={Center}></Route>
{/* 匹配/路径的时候 跳转到/films */}
<Redirect from="/" to="/films" exact></Redirect>
<Route component={NotFound}></Route>
</Switch>
</HashRouter>
</div>
)
}
}
javascript">import React, { Component } from 'react'
export default class NotFound extends Component {
render() {
return (
<div>
404 Not Found
</div>
)
}
}
注意：exact 精确匹配 (Redirect 即使使用了exact, 外面还要嵌套Switch 来用)
1.5 嵌套路由
MyRouter组件中的路由保持不变 当/film模糊匹配到后会进入Film组件
以下代码在Film组件中写即可
javascript"><Switch>
<Route path="/films/nowplaying" component={Nowplaying}/>
<Route path="/films/comingsoon" component={Comingsoon}/>
<Redirect from="/films" to="/films/nowplaying"/>
</Switch>
1.6 路由跳转方式
1.声明式导航
javascript">import React, { Component } from 'react'
import {NavLink} from 'react-router-dom'
export default class Navbar extends Component {
render() {
return (
<div>
<li><NavLink to="/films">电影</NavLink></li>
<li><NavLink to="/cinemas">影院</NavLink></li>
<li><NavLink to="/center">我的</NavLink></li>
</div>
)
}
}
意思是可以监听到地址 如果是/center会给我的这个a标签给加上class="active"的属性，
也可以自定义属性，方便设置css高亮显示
javascript"> <li><NavLink to="/films" activeClassName="Navbaractive">电影</NavLink></li>
<li><NavLink to="/cinemas" activeClassName="Navbaractive">影院</NavLink></li>
<li><NavLink to="/center" activeClassName="Navbaractive">我的</NavLink></li>2.编程式导航
javascript">this.props.history.push(`/center`)
或者导入useHistory
javascript">import {useHistory} from 'react-router-dom'
const history =useHistory()
history.push(`/detail`)
